Van Conversion Wiring: 1,000 Watt Solar System

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This is an overview of how my solar system is wired, the components I used, and where I purchased them.

The 10 solar panels are wired in series-parallel. Each solar panel is 100 watts. I purchased them from here, but they aren’t displaying their catalog anymore. It seems like you have to request a catalog from them now.

solar diagram 4

The numbers correspond to the component table below.

To see how I mounted the solar panels, read this post.

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The rest of the system is wired like this:

whole system

Component Table

Disclosure: This table contains Amazon Affiliate links for products that I used to set up my solar system as described in this post. HurriedYear.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.

numberItemqtyComments
14-Way Lateral Single Fuse Box
1Using this type of fuse box for the solar panels allows me to easily remove the fuses whenever I need to. This is better than searching for messy inline fuses.
2Outback Flexmax 80 FM80 MPPT 80 AMP Solar Charge Controller
1Outback is a trusted name in charge controllers. Some other companies have tried to make cheap knock offs of this charge controller. Setting it up was breeze and it took less than 5 minutes. The components are top notch. Even in 95 degree weather, It did not overheat.
3#12 AWG THHN Stranded red and black wire50 ftUsed #12 for the solar panels
4Xantrex PROWatt 2000 Inverter, Model# 806-1220
1This a 2000 watt pure sine wave inverter with a 3000 watt surge. It is able to run my air conditioner, charge my electronics, and run my induction cook top no problem. I was even running some power tools with it during the build.
5DC toggle switch3Picked these up at Advanced Auto. Just a basic toggle switch. Easy to install by drilling a hole.
6Blue Sea Systems 5031 ST Blade Fuse Block without Cover
1This a basic fuse box that uses ATC fuses. I wish I bought the one with a plastic cover.
7Bussmann (CB185-100) 100 Amp Type III Circuit Breaker
2This is a really safe breaker I used for the battery isolator and fuse box. It makes it easy to disconnect the Isolator and the fuse box for maintenance.
8Bussmann (BP/CB185-80) 80 Amp Circuit Breaker
1I used this 80 amp breaker for the charge controller. It serves as a breaker and a way of disconnecting the charge controller from the system.
9Blue Sea Systems Class T 225 to 400A Fuse Block with Insulating Cover
1Xantrex recommends a 250 amp fuse for the Prowatt SW2000. This fuse block houses the 250 fuse below.
10BLUE SEA SYSTEMS Fuse, Class T, 250 Amp,
1This fuses the inverter. It is high quality and has a very fast reaction speed.
11100 amp mini busbar w/ 6 screws1I used this busbar to bond any of the DC appliances with a metal exterior.
12250 amp busbar w/ 4 studs1This busbar bonds everything to the van via the bolt near the engine.
13Drok 500A Ammeter1The great thing about this meter is that it can display negative values. The meter is always lit blue so it makes a little light at night. It doesn't come with any type of housing, but an Altoid box works great.
14Apex 260 Ah Sealed AGM Batteries3These are the best value AGM batteries that I've found. The company gave me a discount on shipping too. Keep an eye out for coupon codes on their website.
152/0 black wire27 ftOrdered by the Foot.
162/0 red wire 24 ftOrdered by the Foot.
17#4 AWG black wire 11 ftOrdered by the Foot.
18#4 AWG red wire7 ftOrdered by the Foot.
19#14 AWG THHN stranded red, black, and green wire100 ftAll DC appliances and switches used #14 wire.
20Various ATC fusesN/APurchased from Home Depot
21#12 waterproof butt splices with shrink wrapfewPurchased from Home Depot
22#12 appliance lugsfewPurchased from Home Depot
23#14 appliance lugsseveralPurchased from Home Depot
24#14 butt splicesseveralPurchased from Home Depot
25#12 Ring lugs with 5/16 holefewPurchased from Home Depot
262/0 ring lugs2 packsThese Lugs require a special crimper tool.
27#4 ring lugs1 packThese Lugs require a special crimper tool.
28Cole Hersee Battery Isolator1This battery isolator can handle 200 amps which makes it a good choice for Sprinters with the larger alternator option. There are no moving parts so it'll last a very long time. I prefer this isolator over a relay type.
29Dream Lighting LED (6 Pack)1These lights were much brighter than expected. A 6-pack was plenty to completely light up the whole van. They give the option to be screwed in, but I made the holes the perfect size so I was able to clip them in. The leads were soldered in so I just butt spliced them. They do give off a little heat and should have some air space above them.
30Marine Grade Cigarette Lighter Sockets4These have covers to keep dirt, dust, and moisture out. They'll stay clean and last a long time. They come with a little face plate, but I installed them without it.
31120 Volt recepticle2Purchased from Home Depot
3250 ft #14 AWG extension cord1Purchased from Harbor Freight. This was the cheapest way to wire the Inverter to the outlets. Just had to cut one end off.

Everything was screwed to the board after I had a basic idea of where it would go. Then it was as simple as connecting the wires, and putting the fuses in.

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To keep the batteries in place, I reused some of the old anchor points that came with the van to strap them down. I also screwed some wood into the floor to keep them from sliding around.

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I have 4 DC outlets, and 2 AC receptacles. One of the receptacles is for the stove only. It is located under the counter top.

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Four of the lights above the kitchen counter are on one switch, and the other two lights above the bed are on another switch. The lights are wired in parallel. These were surprisingly bright and they easily light up the whole van.

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The current meter shows the net current of the whole system. If it’s positive, the batteries are charging. If it’s negative, the batteries are being discharged. An Altoid box was a perfect fit for the meter.

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This is how it is wired:

current meter wiring

To mount the battery isolator, I moved the horn, and screwed it just above the engine battery.

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Notes:

  • The batteries are wired in parallel giving me 780 amp hours.
  • The solar system, and the Sprinter electric system are both bonded to a single point.
  • All appliances from the fuse box were wired with #14 AWG stranded THHN wire.
  • Anything with a metal exterior, such as the fridge, was bonded to the mini busbar.
  • The 2/0 and #4 green wire is actually black with green tape.
  • All connections are well accessible.
  • I intentionally chose not to put wires behind wall panels.
  • The 2/0 and #4 lugs require a special crimper tool such as the Hammer Crimper Tool (Amazon link). The alternative is to use a hydraulic crimper too, but they are very expensive.
  • A 50 foot extension cord was used to wire the AC receptacles because it was cheap.

I’m getting a lot of questions about how to make decisions regarding solar systems and selecting components. I’m going to save all the reasoning behind my system for another post. Otherwise, this post would be extremely long. If you want to stay tuned for that post, subscribe to my email alerts.

On another note, I’m in Houston catching up on some work. I think I want to head toward Big Bend National park, but that plan isn’t set in stone.

UPDATE 12/20/2016: I now have 3-315 watt  solar panels wired in series instead of the panels mentioned in this post. Other than that, all the wiring is still the same. See this post about the new panels.

Disclosure: This post contains Amazon affiliate Links. HurriedYear.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.

  • The Snake

    Hey Joe, Im very inspired! I had a few questions for you.

    1) Can you run the Air Con all night off the batteries. And on that topic just wondering why you didnt go for the standard roof mounted ac? was it because the solar panels?

    2) What do you do about heat? Or are you just planning on cruising to warm places?

    3) Not clear but is your alternator tied into the charging system as well?

    4) Is it possible to hook up either a DC gas generator to the solar controler for extra power or alternately a a DC charge from a battery charger hooked into an ac electric generator. And lastly can you charge the batteries directly from a 120 volt or 240 volt ac electric plug.

    Keep the faith. i wanna do the same thing as you but I wanna put it on the new Mercedes Sprinter with 4×4 :0

    Still in the planning phase! 🙂

    Cheers
    Dave

    • Joe

      1. No, on batteries alone, I can run the AC about 5 to 6 hours. I didn’t go with a roof mounted AC because they use too much energy, they aren’t stealthy, and they usually end up leaking.
      2. I try to stay in places where the weather is comfortable. I have a small ceramic heater that can take the chill off if I need to. I also have two really warm sleeping bags.
      3. Yes, I have a batter isolator that uses the alternator to charge my house batteries while I drive.
      4. Yes, I think either one would be possible. You can charge your batteries with any source you’d like. I chose not to wire up an AC charging plug because I don’t ever plan to pay for an RV camping spot. I wanted to be as off-grid as possible.
      Thanks for the questions Dave. The 4×4 sprinter would be sweet. Good luck on your build!

      • The Snake

        Hey thanks Joe,

        Let me know if Im bothering you with these questions. I was wondering how you charge the batteries off your alternator. Do you go in to the solar controller or do you just bypass it. Similarly if you were to have an ac hook up for charging would that go through the controller somehow? I have been searching online and cant seem to figure it out. Any suggestion for link would be great.

        One reason why you may wanna consider an AC charger is if you join couchsurfing folks would be very happy to let you use their electric to juice up over night or hile you hang out. Also fill your water tank! I hope you signed up already 🙂 It will really make your trip from great to epic!

        Cheers
        Dave

        • Joe

          Nah you’re not bothering me Dave. To charge the batteries from my alternator, I use a battery isolator. The isolator is wired to the batteries and bypasses the charge controller. To use AC electricity to charge your batteries, you’d need a separate charge controller. The solar charge controllers generally are only designed for solar panels or wind turbines. I’m sure there are some that can use both AC and DC sources, but they’re probably expensive. After some looking around, I’d probably use a CTEK charger.

          It would be pretty nice to juice up at houses over night. Maybe in the future, I’ll do that. Joining couch surfing is still on my To-Do list!

          • Bill

            Hey Joe, Great Build, looks like u did ur homework. Just wondering how u bypass the charge controller when charging from alt. Isn’t the CC and the Isolater connected to the batteries at the same time? Have a Class C now, and thnking of building a Sprinter (thinking less maintaince & stealther). Also, r u familar with Flying J Truck Stops, most have RV parking, but if not they usually let u park overnight on the property. Go in and ask for a book on their locations, it free. Enjoy & thanks for info. Bill

          • Joe

            I’m actually going to write a post about that. I don’t bypass the charge controller. I’ll explain why in the post. I’ll check out those truck stops. Thanks!

        • Scott Mauer

          I found this series on boat and RV power systems the best I’ve seen so far. It covers the kind of issues people are specifically asking about, like how the alternator and solar charge control can work together (or not) to charge the house bank.

          http://roadslesstraveled.us/rv-marine-battery-charging-basics/

          It looks like, Joe, the only thing the isolator is doing is allowing your alternator to change both your van battery and house bank without having them discharge into each other, correct? So when you’re charging from the alternator, you’re only getting whatever intelligence it has built in rather than using a separate charger like this:

          http://sterling-power.com/collections/battery-to-battery-chargers/products/battery-to-battery-chargers

          My understanding, based only on general electrical knowledge and that first link I posted, is that the only disadvantage of Joe’s setup is that the current coming from the alternator will alter the voltage on the house bank, which might confuse the solar charger. The Outback is very smart, and can probably be programmed to overcome this. It doesn’t mean the system won’t work, it could just lead to a situation where the solar system get into the wrong state (Bulk, Absorption, Float) because the power coming from the alternator “artificially” inflates the voltage on the house bank. For instance, if the voltage is high enough, the solar charger might think “these batteries are almost full, I should go to Float now,” and cut back on the power, when, in fact, the batteries could take more current from the solar charger at the moment. Joe said he’s make a more detailed post about how he decided on that setup, and I’m sure that will be covered. After reading up on how complicated these systems are, I understand why that will be a long post. 🙂

          One of the big take aways from reading about how to set this stuff up is that one good way to do it is to have a solar changer and charger that runs on the alternator, and set both of them to the same values for Bulk, Absorption, and Float. The result is that they confuse each other less and more power reaches the batteries sooner without overcharging. Since I can only fit 500 watts on my smaller 144″ 2007 High Top Sprinter, it’s more important to me to squeeze every last drop out of my system, so the added complexity and expense are worth it.

          • Joe

            You’re correct about them possibly confusing each other. For my situation, it isn’t really a problem. I can see how for your situation, you’d like to get an optimal charging rate at all times.

            You’re also correct about the flexmax 80 being very programmable. I’ll cover this soon. You brought up some good points that I need to write about. Currently, I’m drafting a plumbing post so it may be after that.

          • Scott Mauer

            After doing a slew of research, I’ve decided to go the same route you have, namely using the alternator through an isolator to bulk-charge the batteries to the 85% or so possible without a fancy DC-DC converter, and use the MTTP solar multi-stage to get me through absorption and float to however close to 100% SOC is possible. It will mean I have to size my battery bank to the maximum amperage my 400 watts of solar can put out, but it seems better than wasting a lot of money on the DC-DC or an inverter/charger setup. My discussion of that stuff was here:

            http://sprinter-source.com/forum/showthread.php?p=472114

            And a much more comprehensive discussion is here:

            http://sprinter-source.com/forum/showthread.php?t=42013

          • Joe

            Thanks for the links. I’ll use your input when I write my post about it. You might find this helpful when selecting an isolator. I had to modify my isolator to get it to work with the alternator. If you’re in a rush to install it, I can prioritize that post.

          • Joe

            https://uploads.disquscdn.com/images/42931271f29e9a2a39ca06e3c5bb064d22944fcb5c020116d5d11a14e92152c0.jpg

            Thanks for the links. I’ll use your input when I write my post about it. You might find this helpful when selecting an isolator. I had to modify my isolator to get it to work with the alternator. If you’re in a rush to install it, I can prioritize that post.

          • Scott Mauer

            I ordered the same one you got, so that would be really useful info. I’m planning on rolling out in about 10 days. Not much of the conversion will be done by then, but the house pack and isolator are items i’d like to have working. Thanks for offering to up the priority. My Sprinter is also a 2007 NCV3, so our alterntor setup msy be different. I’ve also got a bad positive battery Y cable the replacement for which is coming in today.

          • Joe

            Alright well shoot me an email before you install it and I’ll explain what I did.

          • Scott Mauer

            Thanks! I really appreciate the help.

          • Miloslav Lang

            I’m curious about how you had to modify isolater, when you have a chance could you copy paste that email you guys had. Looking to get one soon. Not sure if you ever wrote a post about it. Thanks!

          • Joe

            It’s a pretty long discussion to paste here. I can forward it to you. Scott, I’ll block out your email address in case you don’t want anyone to see it. Miloslav, shoot me an email from the contact form.

  • mihoangmi

    Hi Joe,
    It is very hard to design a solar system like your. I have a few questions, and hope you are not mind to answer:
    1. How you connect your ceiling LED light, roof fantastic fans to your solar sources? Is that you connect from Solar Charged Controller or from your battery bank. (From #19 on your diagram???)
    2. AC power source will come out from #15 on your diagram ??? (Inverter) and to the AC receptacles (for your cook top, TV, refrigerator …) Is that correct ?
    3. What is the DC receptacle? What you use this for? (12V Refrigerator, ….)

    • Joe

      1: they’re connected to the fuse box (# 6).
      2. Yes that’s correct.
      3. I wired the fridge to the fuse box as well. DC recepticles are for charging my phone and various appliances.

  • Richard Hauser

    Which Air Condiioner did you pick? I don’t think you listed it anywhere. You should add it to the “Van Components”. Does it do heat?

    • Joe

      haier 8000 btu portable air conditioner. You’re right, I haven’t listed it anywhere yet because I haven’t written a post about it haha. It’s on my backlog of 1 million things to do. I’m slacking. No it doesn’t do heat. I have a 900 watt little ceramic heater. I used to use it in my old trailer and it worked great then. I haven’t had to use it in the van yet.

  • Dan

    I need help guys! Electronics turns my head around 20x.. i don’t know what i’m missing.

    I feel like SOMEONE out there can answer my questions with remarkable speed compared to me…

    I’m trying to set up 1000 watts of panels.

    I don’t want to get a kit because like making your own computer i’m sure there’s better products available.

    If i had a 960-1000 watt panel system:

    -What would be the best controller.

    -What would be the best/Safest Inverter.

    -How many batteries (I like the Vmax 155ah deep cycle ones)

    -What should i use for fuses/fuse box

    -and what size wire is safe to put it all together with. I really need to know what wire i will be connecting the controller to the panels because i need to run that wire and start closing up the walls.

    I just want to make sure i put this together with the correct components. My budget is the exact cost. which means i’ll be over guaranteed.) no room to fudge up

    My email is dhwflyer@yahoo.com

    Thank you

    ~Dan

  • MountainFit

    What is the purpose of the circuit breaker between the battery isolator and the battery bank? Wouldn’t the ignition being off basically serve the same purpose? Great blog, really ejoying the build out info.

    • Joe

      1. It gives me the option of not using the battery isolator to charge my aux batteries or working on the isolator safely. 2. If my system tries to draw more than 100 amps from the alternator, the breaker will open. Yes, this can’t happen with the engine off as you said.

      • MountainFit

        thanks for the reply. I’m in the middle of doing a build out myself and in a few weeks I’ll start assembling the battery bank and power distribution.

        after I asked I considered the fact it’s protecting the battery bank from too high of amps, something I didn’t consider since I don’t think the alternator generally ends up getting that much power to the batteries. but turning it off altogether if you solar draws are high enough wasn’t something I thought about.

        Thanks for the reply. Definitely adding a 50amp breaker to my bank from the alternator as well the 150A fuse at the battery.

  • Michael

    Hey Joe, I am planning on shamelessly ripping off your set-up in the next month. My only substitution is going to be a mini-split A/C system. Question about your charge controller, I know it’s a massive and top of the line model but is it high enough amperage? All the sites I have seen say to divide panel wattage by battery voltage. So 1000/12 = 83.33. I know you have since gone down to 945 watts but that would still put you close to 80 amps. My guess is that since the panels are never likely to put out max wattage you should never have any trouble and you have the fail safe of the 80 amp fuse. Any thoughts? PS. awesome build, didn’t think getting A/C for my dog was possible until I saw your build.

    • Joe

      The 80 amp charge controller is definitely large enough and you shouldn’t have to worry as long as you have it fused.